In dynamo-electric machines, a rotating magnetic field is produced by supplying alternating-current power to a stator winding and a rotor is rotated by this rotating magnetic field. In addition, alternating-current power can be outputted from a coil by converting mechanical energy applied to a rotor into electric energy. Thus, a dynamo-electric machine operates as an electric motor or a generator.
As a stator of such a dynamo-electric machine, there is known one so configured that the ends of segment coils are connected by welding (Refer to Japanese Patent Laid-Open No. 2011-151975, for example.). A dynamo-electric machine in which power up owing to temperature reduction can be achieved and further magnetic noise can be reduced by alternatively arranging a stator coil on the inner wall faces of slots along the radial direction (Refer to Japanese Patent Laid-Open No. 2010-112993, for example.).